Photographic material for color photography



Aug. 1, 1939. 1- B. wENDT 2,163,182

PHOTOGRAPHIC MATERIAL FOR COLOR PHOTOGRAPHY Filed Nov, 2s. 1937 d Blue'.Se/zslltive Ema/sion Layr;

Sup/Dort By His Alforneys Patented Aug. 1, 1939` UNITED STATESPHOTOGRAPHIC MATERIAL FOR COLOR PHOTOGRAPHY i Bruno Wendt, Dessau,Germany, assignor, by mesne assignments, to Agfa Ansco Corporation,Binghamton, N. Y., a. corporation of Delaware Application November 26,1937, Serial No. 176,609 In Germany December 9, 1936 6 Claims.

This invention relates to color photography.

For producing subtractive multi-color photographic pictures severalsilver halide emulsion layers containing dyestulf components have been 6superimposed on each other on a carrier, in particular arrangementof'versuper-imposed layers, namely three emulsion layers having twointermediate layers serving as filters or separating layers, has beenfound advantageous. It l has also been proposed to arrange severalsensitive silverhalide emulsions in the form of small particles onacarrier. This latter photographic material has in particular thedisadvantage that the pictures produced' thereonV show a grainyappearance. i

It is an object of the present invention to provide an improvedphotographic material in which the disadvantages incurred with theaforementioned materials are avoided.

`Av further object is a photographic material in which the number .ofnecessary emulsion layers is decreased in comparison with the hithertoused multi-layer materials.

A further object is to provide a material in 25 which the grainystructure of one layer is made to disappear substantially.

Further objects reside in the preferred -and suitable arrangement of thelayers in the photographic element.

Further objects wi11 be apparent from the de` tailed specificationfollowing hereafter.

The invention consists in arranging several sensitive silver halideemulsions having dyestuif components on a carrier, at least one silver35 halide emulsion being in the form of nely subdivided particles andatleast one silver halide emulsion being in the form of a layer. Thus,two

diierently sensitized silver halide emulsions hav-.

Fig. 1 is a diagrammatical View of a multilayer photographic material inan exaggerated scale and Fig. 2 is a diagrammatical view of a singlelayer photographic material according to the invention.

In the gures like characters indicate corresponding parts.

In Fig. 1 a is a support, b represents a gelatin layer, c represents ayellow filter layer, d represents a blueA sensitive silver halideemulsion layer, e indicates theparticles of a silver halide emulsionsensitized to green and containing a dyestuff component fast 'todiffusion caco pable oi' being transformed into a purple dye, I

reference to the accompanying drawing, in which.'

indicates the particles of a silver halide emulsion sensitized to red'and containing a dyestuff component for blue-green of the kind hereinreferred to. n

In Fig. 2 a is a support, g represents a bluesensitive silver halideemulsion layercontaining a dyestuff component capable of yielding avyellow dye, h indicates the particles of a silver halide emulsionsensitized to green and dyed yellow, s'aid particles containing adyestuif component adapted to form a purple picture, i indicates theparticles of a silver halide emulsion sensitized to red and dyed yellow,said particles containing a dyestuifA component for the-blue-greenpicture.

A suitable photographic material, for example, l5 -comprises on acarrier a layer vof a mixture of` particles distributed in gelatin of agreen-sensitive hardened silver halide emulsion provided with a dyestuifformer fast to diffusion and capable of conversion into a purple dyestuiand a red-sensitive hardened silver halide emulsion provided with adyestuff former fast to dilusion and capable of conversion into ablue-green dyestuff, and over this a yellow-dyed layer, and above thisagain a layer of a blue-sensitive silver halide emulsion provided with adyestuif former capable of conversion into a yellow dyestuff.lPreferably the yellow-dyed layer and the layer consisting of ablue-sensitive silver halide emulsion provided with a dyestuif formercapable ol' 30 conversion into a yellow dyestuff are united to a singlelayer by dyeing this single layer yellow and providing it with a dycstuiformer capable of conversion into a yellow dyestuif.

A single layer material for color photography may be made bydistributing emulsion particles of a pre-sensitized yellow-dyed silverhalide emulsion containing a dyestuif former capable of conversioninto apurple dyestuif and the particles of a red-sensitized yellow-dyed silverhalide 40 emulsion containing a dyestuff former capable of conversioninto a blue-green dyestuff in a bluesensitive silver halide emulsioncontaining a dyestuff former capable of conversion to a yellow dyestui.In this case it is of advantage that l the blue-sensitive emulsion-constituent .should constitute more than one-third of the total massvof emulsion.

As dyestuif formers for these silver halide emulsion ,layers there maybe used with advantage components which by introduction of certainradicals have been made fast to diffusion as regards the binding agent.As described in U. S. patent Aapplication Ser. No. 72,718 led April 4,1936, there may be introduced into the dyestu components groups whichlend a substantive character to the molecule of the dyestull' former. Asdescribed in U. kS. patent application Ser. No. 90,726 led July 15,1936, the dyestui components may be made fast to diiusion by introducfing radicals of highly polymeric carboxylicacids or their derivatives.Further, dyestuil' components are fast to diffusion when, as describedin U. S. patent application Ser. No. 94,340 iiled August 5. 1936, theycontain carbon chains of more than carbon atoms or, according to U. S.patent applicationSer. No. 158,860 led August 13, 1937, polypeptideradicals or as described in U. S. patent application Ser. No. 159,518illed August 17, 1937, carbohydrate radicals, or as described in U. S.patent application Ser. No. 164,499 filed September 18, 1937, when theycontain radicals of resins or, as described in U. S. patent applicationSer. No. 166,832 illed October 1, 1937, when they contain sterolradicals. Moreover, dyestuff components fast to diiusion are obtainedwhen the dye-forming groups are coupled to yield a molecule of chainform as described in the U. S. patent application Ser. No. 171,70l ledOctober 29, 1937. There may also be used dyestui components fast todiffusion, as described in U.- Sl patent application Ser. No. 10,704illed March 12, 1935, in which case the dyestui picture is produced byaac-coupling. In like. manner there are suitable silver halide emulsionswhichcontain color iormers fast to dliusion, as

described in U. S. patent application Ser. No.

111,250 filed November 7, 1936, in which the color picture is producedby destroying directly or indirectly the dyestui former or the dyestufiwhich has been formed over the silver image.

For example. if the three emulsions contain leuco-dyestus fast todiffusion which have developing properties for silver halide, there isobtained a dyestuil image in the place of the silver image. The same isthe case when suitable components for the color development are added tovthe emulsion and the development is conducted by means of a 4suitabledeveloper.

There are obtained in` this manner complementarily colored negativesirom which copies may be lproduced onthe same material which arepositives in the correct colors. By destroying the colors rst formed andconverting the residual components;- into dyestufis, there is produced apositive correctly colored picture, also by development of the negativewith a non-dyeing developer togeth'er with subsequent seconddevelopment, for

` example by the. process described in U. S. patent applications ser.No. 100,319 sled september 11,

' 1936, and SeriNo. 148,731 iiled June 17, 1937.

T he material is also suitable for any other process, provided a colorformer suitable for the process used is incorporated with the emulsion,for example if, as described in the German Patent No. 396,485, thereisused a color former which loses its capacity for forming the color atthe places which contain silver, the residue oi4 the -dyestui former isconverted into a positive of correct color.

Y as described in U. S. patent application Ser. No.

.72,714 filed April 4, 1936. Color formers which do not possesssufiicient fastness to diiusion may be madesufiiciently insoluble byaddition of a 'known precipitating agent.

The photographic material herein prescribed is applicable in all casesin which hitherto subtractive multi-color pictures have been produceddirectly'or by means orany component c'olor pictures or othermulti-color copies.

What I claim is:

l. A light-sensitive elemen't for color photography comprising a supportand a plurality of sensitized silver halide emulsions, each of .saidvemulsions containing a dyestuf! component fast to diiusion and capableof forming a dye selected from the group consisting o! quinoneimineandazomethine dyes with the oxidation product of a developer and at leastone light-sensitive silver halide emulsion layer containing a dyestuffcomponent of the same kind.

3. A light-sensitive element for color photography comprising a support,a gelatin layer in direct contact with said support containing hardenedmicroscopic particles of two diiierently sensitized silver halideemulsions, one type v01 par-- ticles being sensitized to green andcontaining a dyestuil' component fast to diiusion capable o! forming apurple dye and the second type being sensitized to red andcontaining adyestuil component fast to diilusion capable of forming a blue-greendye, a silver halide emulsion layer on said gelatin layer containing adyestuii component fast to diffusion and capable of forming a yellowdyestuil.

4. A' light-sensitive element ior color photography comprising asupport, a gelatin layer in direct contact with said support containinghardened microscopic particles of. two diiierently Lcomponent fast todiffusion capable of forming a blue-green dye, a yellow illter layer onsaid gelatin layer, a silver halide emulsion layer vcontain-- 'ing adyestii component fast to diiiusion capable of forming a yellowdyestufi.

5. ,A light-sensitive silver halide emulsion layer comprising a support,a blue-sensitive silver halide emulsion layer containing a dyestu'ficomponent fast to diffusion and capable of forming a-yellow dye,microscopic particles of a hardened `,silver halide emulsion sensitizedto green and dyed yello'w' distributed in said emulsion layer, saidparticles .containing a dyestufi component fast to diil'usion andadapted to form a purple dye, microscopic particles of a hardenedlightsensitive silver Vhalide emulsion dyed yellow distributed in saidemulsion layer, said particles containing a dyestu component fast todiilusion landadapted to form a blue-green dye.

6. A light-sensitive element for color photography` according to claim5, .the blue-sensitive emulsion, layer comprising more than one-third ofthe entire weight of the emulsion.

BRUNO WENDT.

